INCREASE IN THE ADHESION MOLECULE P-SELECTIN IN ENDOTHELIUM OVERLYINGATHEROSCLEROTIC PLAQUES - COEXPRESSION WITH INTERCELLULAR-ADHESION MOLECULE-1

P-selectin (GMP-140) is an adhesion molecule present within endothelia l cells that Is rapidly translocated to the cell membrane upon activat ion, where Ct mediates endothelial-leukocyte interactions. Immunohisto chemical analysis of human atherosclerotic plaques has shown strong ex pression of P-selectin by the endothelium overlying active atheroscler otic plaques. P-selectin is not, however, detected in normal arterial endothelium or in endothelium overlying inactive fibrous plaques. Colo r image analysis was used to quantitate the degree of P-selectin expre ssion In the endothelium and demonstrates a statistically significant increase in P-selectin expression by atherosclerotic endothelial cells . Double immunofluorescence shows that some of this P-selectin is expr essed on the luminal surface of the endothelial cells. Previous work h as demonstrated a significant up-regulation in the expression of the i ntercellular adhesion molecule-1 in atherosclerotic endothelium and a study on the expression of intercellular adhesion molecule-1 and P-sel ectin in atherosclerosis shows a highly positive correlation. These re sults suggest that the selective and cooperative expression of P-selec tin and intercellular adhesion molecule-1 may be involved kt the recru itment of monocytes into sites of atherosclerosis.